Most Helpful Girl

Well first: If you know the girl (if she's your friend or something) talk to her about it.

If you're not sure she is into you and, in this case, if you're not close to each other, then I would tell you to wait or just back off. If she really was into you she would have already make a move.

Also, if she has a boyfriend, you have to understand it is very difficult for her to choose. I mean, if she's not sure she likes you, she probably won't leave her boyfriend.

Even thought she liked you before she was with him, it's in the past now, and the probabilities that she would leave her boyfriend for you are very low..

My opinion in this case is: I wouldn't pursue her until you have absolutely sure she's that into you. Just wait for more signals and she may make a move about it. Try to get a little closer to her (but not too close). Try to understand how she acts around you. Girls are different from each other but I would say that she's into you when: she gets really close to you, smiles a lot, laughs, keeps on having physical contact with you, talks onpenly with you (and many others).